1. Field of the Invention
The invention relates to a control device and control method for an internal combustion engine, which execute engine operation control on the basis of a fuel pressure detected by a pressure sensor.
2. Description of Related Art
A fuel supply system is connected to an internal combustion engine. The fuel supply system is formed of a supply passage through which high-pressure fuel is supplied, a fuel injection valve connected to the supply passage, and the like. In addition, a pressure sensor for detecting a fuel pressure inside the fuel supply system is assembled to the internal combustion engine. Control associated with fuel injection (injection amount control and injection pressure control) is executed on the basis of an engine operating state including the fuel pressure that is detected by the pressure sensor. By so doing, the amount of fuel that is injected from the fuel injection valve and the fuel pressure inside the fuel supply system (fuel injection pressure) are adjusted on the basis of the engine operating state each time.
If there occurs an abnormality in the pressure sensor, it may lead to a decrease in the accuracy of adjusting the fuel injection amount or the fuel injection pressure. Therefore, there is suggested a device that, at the time of an abnormality of the pressure sensor, executes a process of limiting the power of an internal combustion engine (power limiting process) as fail-safe control for the abnormality (for example, see Japanese Patent Application Publication No. 2008-128307 (JP 2008-128307 A)).
There is also suggested a device, or the like, in which a pressure sensor for detecting a fuel pressure in a fuel supply system is provided cylinder by cylinder in an internal combustion engine. In the device, the fuel pressure detected by each of the pressure sensors is used in injection amount control or injection pressure control.
In the device in which the plurality of pressure sensors are installed in the fuel supply system, if the power limiting process is merely executed when there is an abnormality in any one of the pressure sensors, the power limiting process may be unnecessarily executed. That is, it may enter a situation that the power limiting process is unnecessarily executed although it is possible to accurately execute injection amount control or injection pressure control on the basis of the fuel pressure detected by each normal pressure sensor having no abnormality at this time. Such a situation may lead to an unnecessary decrease in the power characteristic of the internal combustion engine, so it is not desirable.